Dungeon Master’s Guide Changes "Dungeon Masters Guide" by Gary Gygax. 1978. TSR Games.
Pg 11 – Generation of Ability Scores: Roll 4d6, 6 times, always taking the highest 3 dice and adding them together – ignoring the 4th die. This will give you 6 attribute scores between 3 and 18. These you can plug into the six attributes as you desire.
Pg 12 – It is strongly suggested that every character have a secondary skill that fits their backstory.
Character ages have been streamlined to fit the human life cycle. All characters start as young adults unless their backstories or class insists otherwise. All will be from 16-40 years old.
Pg 13 – The DM will not check every month to see if a player character gets sick.
Pg 15-16 – Racial tendencies are as the player sees fit.
Pg 18 – Paladins warhorse: The first time a paladin calls his steed it will immediately come to him. If the warhorse is lost for any reason then follow the procedure on page 18.
Pg 23-25 – Ignore alignment.
Pg 39 – Spell recovery is covered in the Players Handbook revisions.
Pg 41 – Protection spells do not prohibit bodily attacks (fists, etc.)
Pg 60 – Listening at doors. Humans, Dwarves, Half-Orcs and Half-Elves have a 1 in 6 base chance to hear a noise at a door. Halflings and Elves hear noises at 2 in 10. Gnomes hear noises at 1 in four.
Pg 61 – Surprise: If a party is surprised then members that were surprised can only act in the surprise round if their initiative comes later than the surprisor.
Pg 75 – There is a new chart for turning undead.
Pg 76-78 - can largely be ignored.
Pg 82 – Characters are dead at –10 hit points.
Pg 86 – There is no longer time or cost involved in gaining levels. Characters level up the morning after enough XP is attained.
Pg 221 – Taste and/or Odor: I suggest changing “musty” to “minty."